For a long time this was farmland and fishermen's cottages. When the English traveller Edward Hawke Locker painted the bay in the 1820s, he found a quiet coast with the mountains rising behind it. That changed as the century wore on and the moneyed families of the interior began building their eccentric seaside residences here, each competing to outdo its neighbour in towers, verandas and ornamental tilework. The district of Heliópolis grew from that fashion. Walking the older seafront today, you pass these belle-époque villas one after another, some restored and some faded, all of them evidence of a time when spending the summer by the Mediterranean was a mark of arrival.

Geography made Benicàssim comfortable long before fashion made it desirable. The Desert de les Palmes range rises just inland, a green wall that blocks the cold north wind and leaves the town in a pocket of mild, sheltered air. The result is a run of gentle beaches, Els Terrers, Heliópolis and Torre Sant Vicent among them, the last named for an old coastal watchtower. The town sits about thirteen kilometres north of Castellón de la Plana, near the northern edge of the Valencian Community, and roughly twenty thousand people live here year-round. Tourism is the engine; the beaches are the fuel.

Benicàssim's modern fame is musical. The Festival Internacional de Benicàssim, launched in the mid-1990s, has drawn a run of the biggest names in rock and electronic music to a town of this size, an outsized reputation for a place you can walk across in an afternoon. In the years since, the Rototom Sunsplash reggae festival has added a second summer wave of visitors. And in a quieter register, the town hosts the Francisco Tárrega classical guitar competition, honouring an instrument that Spain gave the world. Few places manage to be a pilgrimage site for both festival crowds and concert-hall purists.

The name itself is a fragment of older history. Benicàssim begins with the Arabic beni, meaning "sons of," the same root that marks town names all across the former al-Andalus. It is a reminder that this coast was Muslim territory for centuries, its farms watered by techniques the newcomers had brought from the east. Above the town stand the ruins of a medieval castle, worn down to stubs of wall, marking the era when control of the shoreline meant survival. The summer villas and the festival stages are only the most recent layer on a beach that people have valued, and fought over, for a very long time.

Strip away the villas and the festivals and what remains is a straightforward Mediterranean resort, and a successful one. Roughly twenty thousand people live in Benicàssim through the year, but the number swells across July and August as holidaymakers fill the apartments and campsites and spread along the beaches. Tourism is the town's economy, plainly and openly; the seafront, the sheltered water and the reliable sun are the products it sells. What gives the place its particular flavour is the overlap of its two summer traditions. The families who take their annual fortnight by the sea and the young crowds who come for the all-night stages are, in the end, doing what this town's 19th-century visitors once did from the balconies of those ornamented villas, escaping the heat of the interior for the cooler edge of the Mediterranean. Benicàssim has simply been perfecting the art of the summer holiday for well over a century.